The subject matter of the invention is a composition for the oxidative dyeing of hair based on 5-halogen-2,4-diaminoalkylbenzenes as coupler substances and new 5-halogen-2,4-diaminoalkylbenzenes.
Oxidative dyestuffs have achieved considerable importance in hair dyeing practice. The dyes are produced by the oxidative coupling of developer substances and coupler substances in the hair shaft. This leads to very intensive dyeing of hair with very good color fastness. Moreover, various color shades can be produced by combining suitable developer and coupler substances.
2,5-diaminotoluene, 1,4-diaminobenzene, 2-(2'-hydroxyethyl)-1,4-diaminobenzene, 4-aminophenol, 4-amino-2-aminomethylphenol and 4-amino-3-methylphenol are preferred as developer substances.
The coupler substances which are preferably used are m-phenylenediamine and its derivatives, e.g. 2,4-diaminophenoxyethanol, 2,4-diaminobenzyl alcohol, 2-amino-4-(2'-hydroxyethyl)aminoanisole, or pyridine derivatives such as 3,5-diamino-2,6-dimethoxypyridine as blue coupler, 1-naphthol, m-aminophenol and its derivatives such as 2-amino4-chloro-6-methylphenol, 3-amino-2-methylphenol, 4-amino-2-hydroxyphenoxyethanol and 3-amino-5-hydroxy-2,6-dimethoxypyridine as red coupler, as well as resorcinol, 4-chlororesorcinol, 4,6-dichlororesorcinol, 2-methylresorcinol, 4-hydroxy-1,2-methylenedioxybenzene, 4-(2'-hydroxyethyl)amino-1,2-methylenedioxybenzene and 4-hydroxyindole as couplers for the brown to blond range.
Numerous special demands are made on oxidative dyestuffs used for dyeing human hair. The dyes must be unobjectionable in toxicological and dermatological respects and must enable the desired intensity of coloring. Further, a good fastness to light, permanent waving, acids and rubbing is required of the achieved hair dyes. But in every case such hair dyes must remain stable over a period of at least 4 to 6 weeks without being influenced by light, rubbing or chemical agents. Moreover, it is required that a wide assortment of different shades of color can be produced by combining suitable developer and coupler components.
However, the coupler substances presently used in hair dye compositions for producing red and clear blue color tones in particular cannot meet the aforementioned demands in a satisfactory manner.
The 5-chloro-2,4-diaminotoluene described by F. Reverdin and P. Crepieux in Chemische Berichte 33, 2505 (1900) produces pure blue dyeing results with developers of the p-phenylenediamine type; but only extremely weak reddish dyeing results are obtained with developers such as p-aminophenol or its derivatives.
The 2,4-diamino-5-tetrafluoroethoxytoluene known from DE-OS 34 30 513 shows no mutagenic effect in the Ames test, but the depths of color and light fastness of the dyeing results achieved with this coupler substance are not satisfactory.
The coupler substances 2,4-diamino-5-ethoxytoluene or 2,4-diamino-5-(2'-hydroxyethyl)oxytoluene described in DE-OS 36 22 784 possess good toxicological properties and good characteristics with respect to application technology. But the synthesis of these compounds, which is based on 3-hydroxy-4-nitrotoluene, is costly since five reaction steps must be carried out and is therefore unsatisfactory in view of the time required for synthesis (labor costs) and the energy costs.